Securable cover for vehicle lights and method

ABSTRACT

A cover for use in connection with one or more vehicle lights is provided. A lens of the cover contains an electrically activatable material that prevents the transmission of visible light from entering into and reflecting out from the one or more vehicle lights when the electrically activatable material is set to a light inhibiting state. A device holds the lens with the device configured to be releasably or removably secured over one or more vehicle lights. The electrically activatable material of the lens is configured to get to the light inhibiting state such that the lens prevents the transmission of visible light from entering into and reflecting out from the one or more vehicle lights to reduce the observability of the one or more vehicle lights.

PRIORITY CLAIM AND CROSS REFERENCE TO RELATED APPLICATIONS AND METHOD

This application claims priority to parent application Ser. No.12/512,881, titled “SECURABLE COVER FOR VEHICLE LIGHTS,” by Alyn Brownand James Wiff filed on Jul. 30, 2009 and is incorporated by referenceherein.

FIELD OF THE INVENTION

This invention relates to a cover that is releasably securable to lightsof a vehicle such as the front or rear lights on a military or asecurity vehicle. In particular, the invention relates to a releasablysecurable cover that is adapted to block out the reflectivity of thelights on a vehicle such as a security vehicle or military combatvehicle.

BACKGROUND

Conventional lighting for military ground vehicles often utilize OEMlights or an accessory light bar having several high intensity discharge(HID) and/or infrared (IR) lights in a hardwired configurationpermanently attached to the vehicle. The lights are generally fixed inposition at the time of installation and are hardwired into the vehiclepower and switching.

The observability of the vehicle due to reflections off the vehiclelights during certain field operations may be undesirable. For instance,if a military vehicle light is not turned on and the vehicle is in anopen position, detection of the vehicle may occur because of lightreflecting off reflectors behind light bulbs of the vehicle lightmodule.

To address this, certain conventional vehicle systems may use mechanicalcovers which are physically installed on the lights to reduce thereflectivity of light reflectors when the lights are not being used.Both types of covers are installed manually which can be time consuming.These covers must also be repeatedly installed or removed depending onthe mission. Additionally, coverings such as duct tape have been placedover the lights, at certain times, in an effort to reduce lightreflectivity.

Accordingly, there is a need for a cover for vehicle lights, such assecurity or military combat vehicle lights that is adapted to block thereflectivity from light modules on security or military vehicles in aconvenient manner.

SUMMARY

A cover for use in connection with one or more vehicle lights isprovided. A lens of the cover contains an electrically activatablematerial that prevents the transmission of visible light from enteringinto and reflecting out from the one or more vehicle lights when theelectrically activatable material is set to a light inhibiting state. Adevice holds the lens with the device configured to be releasably orremovably secured over one or more vehicle lights. The electricallyactivatable material of the lens is configured to get to the lightinhibiting state such that the lens prevents the transmission of visiblelight from entering into and reflecting out from the one or more vehiclelights to reduce the observability of the one or more vehicle lights.

A method of utilizing a cover in connection with one or more vehiclelights is also provided. A device holding a lens having an electricallyactivatable material is releasably secured over the one or more vehiclelights. The electrically activatable material prevents the transmissionof visible light from entering into and reflecting out from the one ormore vehicle lights when the electrically activatable material is set toa light inhibiting state. The electrically activatable material of thelens is switched from a light passing state to a light inhibiting statesuch that, in the light inhibiting state, the lens prevents thetransmission of visible light from entering into and reflecting out fromthe one or more vehicle lights to reduce observability of the one ormore vehicle lights.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a military vehicle with blackout coverspositioned over military vehicle lights;

FIG. 2 is a perspective side view of an example of the cover installedover a military vehicle light;

FIG. 3 is a cross-sectional side view at section 2-2 of the cover shownin FIG. 2 illustrating an electrically activatable film disposed betweentransparent layers of the cover;

FIG. 4 is a schematic circuit diagram illustrating operation of anexample blackout cover;

FIG. 5 is an exploded view of the cover and a military vehicle lightassembly;

FIG. 6A illustrates one mode of operation of the cover;

FIG. 6B illustrates another mode of operation of the cover; and

FIG. 6C illustrates a further mode of operation of the cover.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of a vehicle 100 with blackout covers 102positioned over vehicle lights. The vehicle 100 may be, for example, amilitary vehicle such as a High Mobility Multipurpose Wheeled Vehicle(HMMWV, or “Hummvee”), or any other vehicle that may be used inconditions in which it is desirable that the vehicle remainundetectable. For example, a Hummvee, or other military transportvehicles, may be used to carry military personnel into areas ofbattlefield conditions. At night, it is desirable to remain undetectableto any enemy personnel that may be in the area. It may also be desirablefor security vehicles, such as vehicles used for special operations,police operations, private security or other security purposes, to bevisually undetectable in certain situations. In such situations, forinstance, a security or military vehicle may turn its lights off.Currently, military ground vehicles use a light bar composed of severalhigh intensity discharge (HID) and/or infrared (IR) lights in ahardwired configuration permanently attached to the vehicle 100 as wellas original equipment manufacturer (OEM) headlights and tail lights. Thelight assemblies typically include reflective elements, particularlybehind the lights to improve illumination. When turned off whileapproaching battlefield conditions, the lighting assemblies may reflectincident light thereby risking detection by enemy personnel. In themilitary vehicle 100 in FIG. 1, for example, a driver or passenger mayactivate the blackout covers 102 to avoid detection due to incidentvisible light reflections when turning the lights off and reduce the IRsignature.

FIG. 2 is a side perspective view of an example of a blackout cover 200installed over a military vehicle light 202. The blackout cover 200includes a lens 204 supported by a bezel 206. The blackout cover 200 maybe affixed, for example, to the military vehicle light 202 using a setof screws 208. In one example implementation, the blackout cover 200 maybe installed over the current light 202 as a kit, replacing the currentlens, or it may be added as a cover. As such, the kit may be a retrofitand left in place once installed. The blackout cover 200 may be affixedusing clips, or adhesives, or using other fixing devices. The blackoutcover 200 may be connected to a switch on an operator panel accessibleby a user in the vehicle. The switch may operate the blackout cover 200independently, or may be connected in parallel with the light 202 foroperation in conjunction with the light 202.

FIG. 3 is a side cross-sectional view of section 2-2 of the blackoutcover 200 in FIG. 2. In this example, the blackout cover 200 includes anelectrically activatable film 220 disposed between transparent layers222 a, b. The blackout cover 200 may be provided as an assembly thatincludes the bezel 206, the screws 208, the transparent layers 222 a,b,and the electrically activatable film 220. The lens 204 may also comepre-fabricated with the electrically activatable film attached to thetransparent layers 222 a, b of the lens. The blackout cover 200 may thenfit over the light 202. The light 202 typically includes a light lens228, a lighting element 230 and a reflective inner surface 232. Innormal operation, the lighting element 230 may be turned ‘on’ togenerate light out through the light lens 228. The reflective surface232 is configured to reflect any incident light through the light lens228. Even if the light 202 is turned ‘off,’ the reflective surface 232may reflect any incident light that should enter via the light lens 238.

In conditions in which the driver of the vehicle desires to beundetectable, the driver or a passenger may switch an actuator thatdarkens the blackout cover 200. The blackout cover 200 may then inhibitvisible light from passing the electrically activatable film 220 ineither direction. Visible light from the lighting element 230 isprevented from passing out of the electrically activatable film 220, orfrom entering into the light reflective inner surface 232 from outside.

In an example implementation, the electrically activatable film 220 mayinclude an electrochromatic polymer (ECP) film, a material used inliquid crystal displays (LCD), and/or organic materials, such as organicmaterials that may be used in LCDs. One example type of ECP materialactivates when a voltage of 1 VDC is applied to the film. An exampleimplementation may alternatively use a simple photocell to drive thesystem such that when the light 202 is turned on, sufficient voltage maybe applied to activate the system and to drive the ECP film to a statethat will pass light. When the light is turned off, the system woulddarken.

As seen, the electrically activatable material may be provided invarious constructions, such as a film that can be disposed betweentransparent layers. Other material constructions may use a vapordeposition process on two adjacent faces of two layers of material andsome with additional liquid material in between, for example. Electricalactivation may be applied to the two layers, for example, causingmigration of certain elements to one layer or the other producing adesired effect. In another example, a suspended particle device (SPD)film may be used with an inverter that produces AC voltage to drive thefilm. The electrically activatable material may also include phasedispersed liquid crystals (PDLCs), materials known as SageGlass® fromSage Electrochromics, Inc., and electrochromatic materials provided byChromogenics AB.

In general, the film may determine how the blackout cover 200 isactivated. Two scenarios include:

-   -   1. A film that is energized to a light inhibiting state;    -   2. A film that is de-energized to a light inhibiting state.

In one example, the film may include multiple layers each havingspecific functions. For example, the film may include anelectrochromopore, an electrolyte layer, and an ion storage layer. Insuch films, the electrolyte layer is typically a liquid or a gel. Inanother example, the film may be a rigid or flexible electrochromaticpolymer that may be cast from solution on a glass or poly(ethyleneterephthalate) (“PET”) substrate. The assembly may then be heated underpressure to laminate the structures. The laminated assembly may includeoptically transparent electrodes, such as for example, indium tin oxide(ITO) layers that may be deposited on the glass or PET substrate andconfigured for connection to a power supply.

In another implementation, the film may include electrochromic glazingconsisting of five thin-film ceramic layers coated directly onto glass.Electrochromic glazing may be implemented similar to low-emissivityglazing used to make energy efficient windows, but in a circuit thatenables switching between light transmission or light blocking asdesired.

In another implementation, the film may a suspended particles device(SPD), which uses small light-absorbing particles, otherwise known as“light valves.” For example, a SPD may be sandwiched between glass orplastic layers and connected via electrical leads to an AC power source.In the ‘off’ state, the particles are randomly distributed in the SPDand block light incident on the glass or plastic wall from passingthrough. In the ‘on’ state, the particles are aligned and allow theincident light to pass through.

In another implementation, a liquid-crystal sheet may be bonded betweentwo layers of glass. The liquid crystal sheet may be connected to apower source. When switched to the ‘on’ state, the voltage rearrangesthe liquid-crystal molecules to allow light to pass through the glass.When switched to the ‘off’ state, the liquid-crystal molecules disperselight making the device opaque.

In some implementations, a selected film may be rigid enough toimplement as a single layer precluding the need for other transparentlayers 222 a,b (in FIG. 3). In other implementations, the film may belaminated on one side of a transparent layer 222 a or 222 b. In certainembodiments, two or more layers of the film placed adjacent to oneanother may be used to achieve enhanced light blocking capabilities.

FIG. 4 is a schematic circuit diagram illustrating operation of anexample blackout cover. FIG. 4 shows a circuit 400 that includes a powersupply 402 as an electrical power source, an electrical coupling device404, and a blackout cover 406. The electrical coupling device 404 may beany device adapted to electrically couple the electrically activatablematerial in the blackout cover 406 to the power supply 402. Theelectrical coupling device 404 in FIG. 4 is shown as a switch that maybe set to one of two states: State A or State B. In State A, theelectrical coupling device 404 is open disabling the transfer of powerfrom the power supply 402 to the blackout cover 406. State A is shown inFIG. 4 to allow incident light to pass through the blackout cover 406.State A represents normal operation in the example illustrated by FIG.4. The vehicle's light may be turned on or off and the blackout cover406 allows incident light to pass through to reflect off the reflectivesurface 232 (in FIG. 3). Light generated by the lighting element 230 (inFIG. 3) is also allowed to pass through the blackout cover 406 in theopposite direction. When the electrical coupling device 404 is closed toState B, power is coupled from the power supply 402 to the blackoutcover 406 to inhibit incident light (including visible light) frompassing through the blackout cover 406. It is noted that the exampleshown in FIG. 4 assumes that the blackout cover 406 includes a film 220that inhibits light when electrically energized. That is, theelectrically activatable material becomes opaque upon being electricallyenergized and the electrically activatable material becomes transparentupon being electrically de-energized. The electrically activatablematerial becomes electrically energized upon reaching a voltagepotential threshold such that the lens does not allow the transmissionof ambient light into the light reflector 232 from the vehicle light202.

In an example in which the film 220 inhibits light when electricallyde-energized, States A and B would provide the opposite operation asthat indicated above. That is, the electrically activatable materialbecomes opaque upon being electrically de-energized and the electricallyactivatable material becomes transparent upon being electricallyenergized. The electrically activatable material becomes electricallyde-energized upon removal of a voltage potential threshold such that thelens does not allow the transmission of ambient light into the lightreflector 232 from the vehicle light 202.

In another example, the film 220 may be in one state, such as opaque ortransparent, with a voltage having a first polarity (for example, +/−)applied to it, and switch to the other state, such as transparent oropaque, when the polarity is switched (for example, to −/+).

The electrical coupling device 404 in FIG. 4 is depicted with anactuator 404 a, or actuation device, illustrating alternative ways tochange the state of the electrical coupling device 404. For example, theelectrical coupling device 404 may be an on/off switch in a controlpanel accessible by a user in the cabin of the vehicle. The user maymanually switch the electrical coupling device 404 from off to on, orvice versa depending on whether the user desires to be detectable.Referring to the example described above, the user may switch the switch404 from State A (off) to State B (on) to block light and blackout thevehicle.

The switch actuator 404 a may also be implemented as a toggle switch, abutton, an actuator on a touch panel screen, or a sensor such as aphotocell sensor with switch capabilities upon sensing light activity.The actuation device 404 a may be any actuator employed to initiatechange of operation modes.

In another example, the switch actuator 404 a may be the same lightswitch that operates the vehicle lights. The vehicle lights may beconnected to state A such that the blackout cover is enabled when thevehicle lights are turned off. In another example, states A and B may bereversed and the vehicle lights may be connected in parallel to theblackout cover 406.

The switch actuator 404 a may be a hardwired switch, a softwarecontrolled switch, or a wireless control. For example, the switchactuator 404 a may be an electronic switch connected to a controllerthat controls the blackout cover 406 systematically. For example, acontrol panel may be configured to place a vehicle in a battlefieldcondition such that activation of the blackout cover 406 is one functionperformed to place the vehicle in battlefield condition. In anotherexample, the switch actuator 404 a may include a common light switchthat is in battlefield mode when switched to one state to both darkenthe light modules as well as turn the lights off. The electricalcoupling device 404 may also be implemented using a wireless connectionto a control panel that may or may not be located in the vehicle itself.In alternative arrangements, electrical coupling device 404 may simplybe an electrical conductor, such as a cable or copper wiring toelectrically couple the electrically activatable material to a powersource 402.

The power supply 402 may include the vehicle power supply coupled to thecover 406 via a control panel in the vehicle. The power supply 402 mayalso include a vehicle battery coupled via a control panel of thevehicle. The power supply 402 may also include an accessory batterycoupled via a control panel adapted to re-charge the accessory batterybased on conditions of a vehicle battery.

FIG. 5 is an exploded view of a cover and military vehicle lightassembly 500. The assembly 500 includes a bezel 502 for supporting theblackout cover assembly, a first transparent layer 504, anelectrochromatic layer 506, a second transparent layer 508, and a lightassembly 510. The light assembly 510 includes a light lens 512, asupport structure 514, a light generating element 516, and a reflectiveinner surface 518. The electrochromatic layer 506 may be laminated tothe transparent layers 504, 508 and fixed to the bezel 502 by a knownfixing technique (for example, adhesive, screws, clips, etc.). Thetransparent layers 506, 508 may made of a glass or polycarbonatematerial, or of a glass material such as plexiglass or a bulletresistant glass. The blackout cover assembly may then be fixed to thelight assembly 510 using screws 520, or any other fixing technique. Aspacer 522 may also be provided to create space and an air gap betweenthe lens 204 of the cover and light lens 512 of light assembly 510. Inan alternative configuration, the blackout cover assembly 500 mayinclude at least one rim adapted for releasable securement of theblackout cover 600 to the vehicle light. The releasably securable rim,for example, may be formed from a metal, rubber molded or compositematerial.

FIGS. 6A-6C schematically illustrate operation of a blackout cover 600in an example implementation. FIGS. 6A-6C each show a blackout cover 600mounted on a vehicle light assembly 602. The vehicle light assembly 602includes a reflective inner surface 604.

FIG. 6A shows the blackout cover 600 in a first state in which thevehicle light 602 operates normally and detection of the vehicle is nota concern. The vehicle light 602 may be ‘on’ causing light to begenerated outward through the blackout cover 600. However, when thelight 602 is ‘off,’ incident light 608 may pass through the blackoutcover 600 and reflect off of the reflective inner surface 604 of thelight 602. Such reflected light would enable detection of the vehicleeven when the light 602 is ‘off.’ Depending on the material used for theelectrochromatic layer of the blackout cover 600, the first state may beenabled by energizing, or de-energizing the blackout cover 600 asdescribed above with reference to FIG. 4. When the blackout cover 600changes states, the state of a light source 616 may or may not change.For example, the light source 616 may switch off when the blackout cover600 switches to a blackout state. Or, the light source 616 may be lefton even thought the blackout cover 600 has switched to a blackout state.

FIG. 6B shows the blackout cover 600 in a second state in which thevehicle light 602 is in the ‘off’ state. However, detection of thevehicle is not desired and as shown in FIG. 6B, incident light 608 isblocked by the blackout cover 600 while in the second state. By blockingout the incident light 608, light is inhibited from being reflected offthe reflective inner surface 604 of the light 602 diminishing the chanceof detection in the dark during battlefield conditions.

FIG. 6C shows an application in which the blackout cover 600 includes anelectrochromatic material that selectively allows light havingwavelengths in a selected range to pass through while blocking light inother wavelengths ranges. In FIG. 6C, selected incident light 610 in aselected wavelength range is allowed to pass through by the blackoutcover 600 and reflect off the reflective inner surface 604 as reflectedlight 611. Other incident light 608 in another wavelength range isblocked, such as visible light, for example. In the applicationillustrated by FIG. 6C, the selected wavelength range for the incidentlight allowed to pass at 610 may be for light in the range from 700nanometers to a 1200 nanometers. In addition, light generated by thelight source 616 may continue to emit if left on after the blackoutcover 600 changes states. If the light is left on, infrared light 612emitting from the light source 616 may pass through the blackout cover600, but visible light 614 emitting from the light source 616 may beblocked.

The selected wavelength may be in the infrared spectrum, for example.While light that is visible with the naked eye may be blocked at 608,light in the infrared may be allowed to pass. In this manner, a vehiclemay be detected by friendly personnel equipped with detectors able todetect the infrared emitted by the vehicle's lights. The visible lightemitted by the vehicle's lights would be blocked allowing the vehicle toescape detection by enemy personnel that lack detectors of infrared,such as for example, night vision goggles (NVG).

As seen, a method of utilizing a blackout cover to reduce and eliminatethe ability to see vehicle lights resulting from visible lightreflecting off the vehicle lights during certain modes of operation isprovided. A lens is positioned within a bezel of the cover. The lens hasan electrically activatable material such as a layer of electrochromatic film positioned between layers of transparent glass material.The electrically activatable material prevents the transmission ofvisible light from entering into and reflecting out from the vehiclelight when the electrically activatable material is set to the lightinhibiting state. In some embodiments, more than one layer of theelectrically activatable material may be used to enhance light blockingcapabilities. The electrically activatable material is electricallycoupled to an electrical power source. The electrically activatablematerial is able to be switched from a light passing state in whichlight is permitted to pass through the lens to a light inhibiting statein which the lens prevents the transmission of visible, light fromentering into and reflecting out from the vehicle light to reduceobservability of the vehicle light.

In one example, the electrically activatable material becomes opaquewhen electrically energized and becomes transparent when it isde-energized. In alternative arrangements, the electrically activatablematerial becomes opaque when it is electrically de-energized and becomestransparent when it is electrically energized. The electricallyactivatable material of the lens may selectively pass light of aparticular spectrum (such as infrared light in the 700 nanometer to 1200nanometer range) through the lens and block out light at wavelengthsoutside the spectrum. The cover may be adapted for retrofitinstallation. For instance, the lens may be placed in a bezel that holdsthe lens in position and the bezel may be releasably or removablysecured to the vehicle lights.

The foregoing description of implementations has been presented forpurposes of illustration and description. It is not exhaustive and doesnot limit the claimed inventions to the precise form disclosed.Modifications and variations are possible in light of the abovedescription or may be acquired from practicing the invention. The claimsand their equivalents define the scope of the invention.

What is claimed is:
 1. A cover for use in connection with one or more vehicle lights, comprising: a lens having an electrically activatable material in which the electrically activatable material prevents the transmission of visible light from entering into and reflecting out from the one or more vehicle lights when the electrically activatable material is set to a light inhibiting state; a device that holds the lens, the device adapted to be releasably or removably secured over the one or more vehicle lights; and wherein the electrically activatable material of the lens is adapted to be set to the light inhibiting state such that the lens prevents the transmission of visible light from entering into and reflecting out from the one or more vehicle lights to reduce the observability of the one or more vehicle lights.
 2. The cover of claim 1 wherein the electrically activatable material is an electrochromatic material.
 3. The cover of claim 2 wherein the electrochromatic material comprises at least one layer of electrochromatic film.
 4. The cover of claim 3 wherein the at least one layer of electrochromatic film is affixed to at least one layer of a transparent material of the lens.
 5. The cover of claim 4 wherein the transparent material is a glass or a polycarbonate material.
 6. The cover of claim 5 wherein the transparent material is glass material comprising at least one of: (a) plexiglass; and (b) bullet resistant glass.
 7. The cover of claim 3 wherein the electro chromatic film is disposed between layers of transparent material of the lens.
 8. The cover of claim 1 wherein the device includes a bezel releasably secured to the one or more vehicle lights by at least one releasably securable rim.
 9. The cover of claim 8 wherein the releasably securable rim is formed of a metal, rubber molded material or composite material.
 10. The cover of claim 1 wherein the device includes a bezel removably secured over the one or more vehicle lights by screws affixed to a lighting assembly.
 11. The cover of claim 1 wherein the vehicle lights are military combat vehicle lights or security vehicle lights.
 12. The cover of claim 11 wherein the electrically activatable material is adapted to selectively pass light of a particular spectrum and block out light at wavelengths outside of the spectrum.
 13. The cover of claim 12 wherein the electrically activatable material selectively passes light ranging from 700 nanometers to 1200 nanometers.
 14. The cover of claim 1 further comprising a coupling device adapted to electrically couple, at least in part, the electrically activatable material to an electrical power source; and an actuator that sets the electrically activatable material of the lens to the light inhibiting state in response to user operation.
 15. A method of utilizing a cover in connection with one or more vehicle lights comprising: releasably securing a device over the one or more vehicle lights, wherein the device holds a lens having an electrically activatable material in which the electrically activatable material prevents the transmission of visible light from entering into and reflecting out from the one or more vehicle lights when the electrically activatable material is set to a light inhibiting state; and switching the electrically activatable material of the lens from a light passing state to the light inhibiting state such that, in the light inhibiting state, the lens prevents the transmission of visible light from entering into and reflecting out from the one or more vehicle lights to reduce observability of the one or more vehicle lights.
 16. The method of claim 15 wherein the electrically activatable material further comprises at least one layer of electro chromatic film.
 17. The method of claim 16 further comprising positioning the at least one layer of electrochromatic film between layers of transparent material of the lens.
 18. The method of claim 17 wherein the transparent material is glass material comprising at least one of: (a) plexiglass; and (b) bullet resistant glass.
 19. The method of claim 15 wherein the vehicle lights are military combat vehicle lights or security vehicle lights.
 20. The method of claim 15 further comprising selectively passing light of a particular spectrum through the lens and blocking out light at wavelengths outside the spectrum.
 21. The method of claim 20 further comprising selectively passing light ranging from 700 nanometers to 1200 nanometers through the lens. 